In the technology area of home media playing and streaming, there are already some technologies supporting media content streaming from source device A to render device B, and screen mirroring from source device A to render device B, such as AirPlay, Miracast, DLNA.
But, there exists some limitations during the ongoing playing of content from the source device A to the render device B as follows:
1) it's not easy for a new render device e.g. C or more to smoothly join the playing process together with the render device B, i.e. simultaneous play;
2) it's not easy for a new render device e.g. C or more to uninterruptedly switch the playing process from the render device B to the other render device C.
For limitation 2), there probably exist some solutions, e.g. including steps of;
a) stop the playing process from the source device A to the render device B. And the stop point was recorded somewhere which is then notified to C;
b) the render device C is triggered to play the same media content from A;
c) the render device C seeks the last stop point of the media content previously played at the render device B; and
d) a new unicast connection is established between the source device A and the render device C to continuously streaming and playing the media content.
This above typical streaming redirecting technology in fact initiates a new playing streaming from the source A to the render device C. It involves some interruption of the play process, even though probably the hardware (HW) performance of the source device A and the render device C can be powerful enough to reduce the interruption impact to user experience.
Besides, the above typical solution is also not easy to support or resolve the above limitation 1), that is, dynamically joining/leaving for multi-screen simultaneous playing.
Some other screen switching technology is mirroring, i.e. to capture the source device A's screen image/frame and send it to the render device B or C for real-time displaying. This technology requires very powerful HW capability of dedicated GPU (Graphics Process Unit) in both devices, which will raise the device cost. Besides, this technology also has its inherently drawback of graph quality loss during the encoding and decoding of captured screen frame.